This section provides background information related to the present disclosure which is not necessarily prior art.
Omnidirectional antennas may include an inverted cone or shorted inverted cone, which provides very good omnidirectional radiation patterns over a broad bandwidth. But it can be very challenging to design and build an omnidirectional antenna for low Passive Intermodulation (PIM), which is dependent on the frequency range of the antenna. Typical PIM level specifications of in-building antennas may be −150 dBC (decibels relative to carrier) with two tone carriers of 43 dBm (decibels-milliwatts).
Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.